Diagnosis of dementia by widely used screening tools and routine psychiatric or neurologic interview has error rates of up to 50%. In addition, they can require highly skilled personnel for administration and all too often yield incomplete, unsystematic and insensitive data. Previous collaborative research carried out by NeuroComp Systems, the UC Irvine Study Group and the UC Irvine Memory Disorders Clinic has resulted in the development of a multiphasic dementia battery which exhibits 98% sensitivity and 97% specificity in distinguishing early (developing) senile dementia of the Alzheimer's type (SDAT) from age-matched controls. Phase I is designed to complete development of a prototype hardware- software system (Interactive Dementia Battery-IDB) that allows patients to interact with a computer using an unattached conductive stylus. The software package will be composed of six separable modules: 1) a branching, structured neurologic interview, 2) a standardized, quantitative mental and social function status examination, 3) a dementia screening battery and 4) memory, 5) visuopatial test and 6) language assessment. The microcomputer-based hardware ensemble incorporates dual high resolution monitors (one each for the test administration and one for the patient) with high resolution touch screens that will allow a patient to interact with displayed graphic figures and test items directly in real time. Both of these features will greatly speed, simplify and standardize test administration, test scoring, report generation and resultant data bases. The IDB system will be capable of displaying nearly any graphic image or figure and will incorporate a unique software driver that will permit complex 2-way (patient-computer) and 3-way (clinician-patient-computer) interactions. In Phase II, an integrative report writer designed to facilitate clinical interpretation, and record keeping will be implemented. In addition, a database analysis package will be completed. Further refinement of software, hardware and diagnostic algorithms will be accomplished through field testing at several established centers.